Cut-Off Grade Optimisation at Ad‘Duwayhi Mine in Saudi Arabia

Abstract

In terms of the gold mine in Saudi Ariba about 83 % of gold are being mined out through open pit mining methods. In a mining operation, the grade tonnage distribution of the deposit indicates that not all the material inside the open pit can be processed. Given this grade variability, it is critical to identify ore and waste correctly. In 2018, Saudia Ariba developed a new economic vision focus for developing the gold mining sectors. Therefore, to guarantee achieving the expectations from gold mining industry in terms of techno-economic demands, cut-off grade optimisation is the key. The economic requirement aims towards the maximisation of the return on investment, while techno-economic sustainability aims towards the maximisation of resource recovery. Over the last six decades, tremendous progress has been observed in cut-off grade optimisation. In this study, cut off grade optimisation was used to maximise the value of Ad‘Duwayhi mining operation based on a finite resource. The traditional approach to cut off grade calculation was compared with the optimise approach of a cut-off grade, and in so doing, there was an improvement in cut-off grade leading to improved gold produced by 8%. The results of the calculation were modelled in the comparison showing 8% improvement in the net present value. This means that for a given set of design, production and geological parameters, the classification of ore and waste is what ultimately determines the value of a mining operation.